In 1940, Superman’s popularity had hit full steam. The character was appearing monthly in ACTION COMICS, a quarterly self-titled comic, seven days a week in newspapers across the country and entertaining listeners three times via his audio adventures on the radio.
The character’s popularity spurred Detective Comics and New York World’s Fair organizers to conduct “Superman Day” on July 3, 1940. The day featured Superman-themed events and contests, as well as special guests, including a visit from Superman himself. (Check out episode 58 of The Thrilling Adventures of Superman for more information about the day’s events.)
Both Harry Donenfeld and Jack Liebowitz were in attendance at the New York World’s Fair that day … as was Superman’s co-creator, Jerry Siegel! YouTube user ReelNostalgia has posted some Kodachrome footage from the day. A brief glimpse of Siegel can be seen at the 2:08 mark, with a slightly longer appearance, Siegel posing with Liebowitz, at 2:25.
Unfortunately, to the best of my research, Joe Shuster was not in attendance that day at the Fair.
Film of Siegel (or Shuster, for that matter) from this time period is extremely rare — and color footage even moreso. Thanks to Superman Fan Podcast host Billy Hogan for the heads-up on this great discovery.